In semiconductor manufacturing and other industries, it is desirable to produce uniform coatings on substrates and other work pieces. This is particularly true in semiconductor manufacturing operations for coating substrates with a photoresist film. This is also true for other semiconductor coating operations such as spin-on glass or other spin-on dielectric coating operations, the application of various anti-reflective coating (ARC) materials, and various other coatings of permanent or sacrificial films used in semiconductor manufacturing. These films benefit from a uniform thickness throughout the substrate upon which they are coated. A uniform thickness throughout a substrate is particularly useful for a photoresist film, in particular, so that the dimensions of features produced using the photoresist coating as a mask, are uniform throughout the substrate including on the numerous integrated circuit devices formed on the substrate. This is especially true as substrate sizes become larger. With larger substrate sizes, there are more individual integrated circuits on a substrate and a greater area to be uniformly coated.
Coating operations are carried out using coating apparatuses that include a dispenser arm and a chuck that retains a substrate. The dispenser arm is positioned over the chuck and an amount of fluid is dispensed through a dispense nozzle onto the substrate received on the chuck. The chuck is then typically rotated in an attempt to uniformly spread the dispensed material across the substrate. These are delicate operations and if the dispenser nozzle is not centered over the chuck and in proper horizontal and vertical alignment with the chuck and substrate, a non-uniform coating can result.